Thousands lined the streets and looked on from balconies above Oxford Street, waiting excitedly for the revving motors of Dykes on Bikes to signal the official start of festivities.

The dulcet tones of the Village People, Katy Perry and Lady Gaga could be heard floating over Hyde Park.

And when the 12,500 participants finally did come skipping, dancing and rolling down Oxford St, the full spectrum of queer diversity was on display as firefighters danced to Billy Joel's We Didn't Start the Fire, rainbow families followed a Gayby Baby float, and both ends of the political spectrum made their colourful statement on the famous strip.

Robyn Foster and fellow members of the Wollongong celebrant community joined the parade down Oxford St in support of marriage equality.

Nicole Dillon, 39, had travelled from the Sunshine Coast especially to march with the 'Camp Berra' float, to support the ACT's AIDS Council. After watching on from the sidelines last year, she was looking forward to her first time marching.

The float's organiser, Rachel, said this was her 36th year marching in the parade. She hopes to raise money to build a memorial garden in Canberra, commemorating loved ones who have died of AIDS.

"I like the idea of the Mardi Gras because it's freedom," she said. "You can express yourself for who you are - no more hiding in the closet."

Feather-clad Lek, a 50-year-old from Five Dock, made ornate costumes for all those on his float.

"Every year I have to make costumes for all of my friends," he said.

Each year, Lek returns to his native Thailand and brings back feathers for this task.

At a press conference ahead of the parade, and flanked by Labor members wearing shirts reading "It's Time for Marriage Equality", Shorten and Plibersek called on the Turnbull government to allow a conscience vote on marriage equality.

"We don't need to wait until a federal election to have marriage equality," Mr Shorten said, criticising the federal government planned plebiscite.

"We can have a conscience vote in the next sitting week of parliament."

Mr Shorten promised to introduce a law to make marriage equality a reality within 100 days of the election of a Labor government.

Shorten and Plibersek's press conference was interrupted by protesters from the 'No Pride in Detention' float.

"We're here, we're queer, refugees are welcome here," they chanted.

That float was just one behind Mr Shorten's Rainbow Labor float.

Prime Minister Malcolm Turnbull also became the first sitting Prime Minister to attend a Mardi Gras. While he didn't march, Turnbull told reporters he had been coming to the parade "since last century" and that he would not be attending any after-parties.

Linda Burney, who is hoping to make the switch from state to federal politics at the next election, danced in a platinum blonde bob wig with the First Nations float. NSW Greens MP Jenny Leong, NSW independent Alex Greenwich, and Sydney's Lord Mayor Clover Moore were among the politicians who also marched.